Implement timing frames.

webrtc/modules/video_coding/generic_decoder.cc

Index: webrtc/modules/video_coding/generic_decoder.cc
diff --git a/webrtc/modules/video_coding/generic_decoder.cc b/webrtc/modules/video_coding/generic_decoder.cc
index 5969f2369684030cd30c1f8a281860dc1e4ce805..e24d19dcf7879eb89257053575c63279808b7101 100644
--- a/webrtc/modules/video_coding/generic_decoder.cc
+++ b/webrtc/modules/video_coding/generic_decoder.cc
@@ -85,6 +85,30 @@ void VCMDecodedFrameCallback::Decoded(VideoFrame& decodedImage,
   _timing->StopDecodeTimer(decodedImage.timestamp(), *decode_time_ms, now_ms,
                            frameInfo->renderTimeMs);
 
+  // Report timing information.
+  if (frameInfo->timing.is_timing_frame) {
+    int64_t ntp_offset =
+        _clock->CurrentNtpInMilliseconds() - _clock->TimeInMilliseconds();

[sprang_webrtc, 2017/05/31 11:12:55]

This will be racy, in the sense that the offset may vary a bit from frame to
frame. I have a vague memory if this offset being cached somewhere...

[ilnik, 2017/05/31 15:17:45]

I think nothing can be done here, as we are using estimated ntp time to adjust
sender timestamps either way, some degree if imprecision is unavoidable.

[sprang_webrtc, 2017/06/05 14:39:20]

Some imprecision is unavoidable, agreed, but we can keep that imprecision
constant. Just cache this offset as a const member of the class for instance.
Otherwise we're introducing extra jitter (and calling timing functions
unnecessarily often).

[ilnik, 2017/06/07 14:25:03]

Oh, I've got that you mean. I didn't find any cached values like that, so It's
now cached in VCMDecodedFrameCallback.

+    // Convert remote timestamps to local time from ntp timestamps.
+    frameInfo->timing.encode_start_ms -= ntp_offset;
+    frameInfo->timing.encode_finish_ms -= ntp_offset;
+    frameInfo->timing.packetization_finish_ms -= ntp_offset;
+    frameInfo->timing.pacer_exit_ms -= ntp_offset;
+    frameInfo->timing.network_timestamp_ms -= ntp_offset;
+    // TODO(ilnik): Report timing information here.
+    // Capture time: decodedImage.ntp_time_ms() - ntp_offset
+    // Encode start: frameInfo->timing.encode_start_ms
+    // Encode finish: frameInfo->timing.encode_finish_ms
+    // Packetization done: frameInfo->timing.packetization_finish_ms
+    // Pacer exit: frameInfo->timing.pacer_exit_ms
+    // Network timestamp: frameInfo->timing.network_timestamp_ms
+    // Receive start: frameInfo->timing.receive_start_ms
+    // Receive finish: frameInfo->timing.receive_finish_ms
+    // Decode start: frameInfo->decodeStartTimeMs
+    // Decode finish: now_ms
+    // Render time: frameInfo->renderTimeMs
+  }
+
   decodedImage.set_timestamp_us(
       frameInfo->renderTimeMs * rtc::kNumMicrosecsPerMillisec);
   decodedImage.set_rotation(frameInfo->rotation);
@@ -151,6 +175,7 @@ int32_t VCMGenericDecoder::Decode(const VCMEncodedFrame& frame, int64_t nowMs) {
     _frameInfos[_nextFrameInfoIdx].decodeStartTimeMs = nowMs;
     _frameInfos[_nextFrameInfoIdx].renderTimeMs = frame.RenderTimeMs();
     _frameInfos[_nextFrameInfoIdx].rotation = frame.rotation();
+    _frameInfos[_nextFrameInfoIdx].timing = frame.video_timing();
     // Set correctly only for key frames. Thus, use latest key frame
     // content type. If the corresponding key frame was lost, decode will fail
     // and content type will be ignored.